Calcining apparatus



' Nov. 6, 1923.

R. D. PIKE CALCINING APPARATUS Filed Deo. 20. 1922 Cil latented Nov.. 6, 1923.

.UNET TTS ROBERT D. PIKE, OF SAN FRANCISCO, CALIFQRNIA.

caLoNINa APPARATUS.

Application filed December 1922. Serial No. 808,068.

To all whom it may concern:

Be it known that I, ROBERT D. PIKE, a

a citizen of the United States, residing incity and .county of San Francisco and State of' California, have invented certain new and useful Improvements in Calcining Apparatus, of which the following is a specifi cation.

'The hereinafter described invention relates to a calciner of the multiple hearth type, designed more particularly for adaptation to the economic calcination of carbonate rocks,` such as magnesite, and calcite, and the invention is more specifically adapted to the requirements of the apparatus for calcining and clinkering of carbonaceous rocks set forth and described in my pending application, Serial No. 572,895, filed in the United States Patent Office under date of July th, 1922, for an apparatus for calci-ningand clinkering, and in which apparatus the hot calcined material is iminediatelv passed through a rotary kiln for clinkcring, thence transferred into and passed through a cooler, the larger portion of the hot air from the cooler being delivered to the calciner for combustion of the fuel therein. while the smaller portion of the hot air from the cooler passes to the rot-ary kiln for combustion of the fuel therein, and the products of combustion from the rotary kiln or clinkering member being delivered therefrom into, the calciner above the zone of combustion.

The objects of the present invention are to provide a calciner of the class mentioned, (of the multiple hearth type wherein the hearths are arranged in staggered relation) to provide a lower hearth so arranged or situated rela-tive to its adjacent upper hearth as to give ample proportions or area for complete combustion of the required fuel at a high temperature; to protect the moving parts from destruction by the high temperature of the flame within the combustion chamber of the calciner; to reduce radiation losses from the flame to the outside atmosphere to a minimum; to provide for the passage of hot gases of combustion or gases of any sort from an outside source, upwardly through an annular flue or wall of the calciner surrounding the lowermost or combustion hearth and discharging same over the neatl hearth above. and so construct the rabble arm working over the lowermost hearth of the series of hearths as to materially prolong the life and the elliciency thereof.

In order to comprehend the invention reference should be had to the accompanying sheets of drawings, wherein:`

Figure l is a broken elevation part sectional View of ay multiple hearth type of calciner with my improvements applied thereto.

Figure 2 is a. view in elevation of one of the rabble arms situated within the combustion chamber for movement over the lowermost heart-h of the calciner.

Figure 3 is a vertical sectional view taken on the line 3 3, Fig. 2 of the drawings and viewed in the direction of the arrow.

Figure 4 is a similar view taken on the line 4-4, Fig. 2 of the drawings and viewed in the direction of the arrow.

Figure 5 is a detailed sectional view illustrating a modified Aform of burner arrangement for the combustion chamber of the apparatus.

In the drawings the numeral 1 is used to indicate the outer shell or casing of the calciner` and 2 an insulating lining interposed between the inner wall surface of the shell or casing 2 and the refractory lining 3 of the calciner. The hearths arranged in superposed staggered relation are indicated by the numeral 4, which hearths are projected inwardly from the refractory wall lining 3 of the calciner. Through the apparatus is extended a vertically disposed rotating shaft or column 5 which is supported and driven by mechanism not shown but of the usual type for imparting rotary movement to said column, which central column supports and carries the rabble arms 6 radially projected therefrom to overlie the hearths 4 of the calciner. The arrangement and disposition of the hearths 4 and equallyT so the rabble arms 6 conform to arrangement and construction as in the calcining apparatus set forth and described in my said pending application No. 572.895 and call for no specific description herein, the said rabble arms being of the hollow type and air being received therein from the rotating hollow column 5 and circulating therethrough for cooling purposes. Like in the calciner of my said pending application the hollow rotating column 5 is protected from the etect of the high temperature of the atmosphere passing upwardly through the calciner by means of the refractory lin- :jeezed mhhie 'teeth l f if fw i il i C il 8 is pieiiei'zihiy formed of hard hurnt 'iieiy heow 'ihe maten fieiimmii een fi he :ff i heaih Je of he upnuieus und h v ihe :Lemon ihereoi ih niaisfiiiii ie: iiik *A h h@ ioe extension and dropped ofi the Tear o #he rehhie tooh Wiih 0.- Qomponeni of movement outward ziions the Said iahhe arm, ihm io he :lione ine faire 'C '1 Each oi me izihhie arms 8 i3 provided 'with an end mein 5,1 L? 'which Serves the 'lf'uncion of :i pushei and carries Iihe oaicined inaeiiai which has reached he outside o he heerh 9 around 'io the chsehnrge oui'ie opening 19 of ihe cuisiner and through which he eaioined inuiezia is discharged.

Surrounding ihe ioueiniesi; hearth Soi" ihe Cuisiner annular i'eiiieaiy eiiieneeii ",ie '2Q whieh fiue. Where he eaieiner is utiiizeii in eonjuneiion with u, ehnkeiing appaizu'us, is usually Supplied u'irh hot gases of eonihuetion from the said (flinke-ih ing7 meinhei the saine heingr deiiveied ino h im* fine Q0 Through fi .Quiizihle pas- Yen'nff 21. "m gzigee of minhuiion (iein' and ev point 'the series of ed, ion/11 *i supply.

lxeep' ihe p'ovision. coinhusiion chamber between *the 'he enlcinei un@ fif-iiih o., adjacent thereto, the providing he utiiirifiion of i ntensiy wihin the said, eo muli so pioeeiing he ove? ihe iowei'niost einem; of he nppeizizus sei; 'l scribed in my hefoie-mentionef' pending pheet'ion ho. ihiie have i, iaed und desfiiheii the prefer'ed manner of iui'ioiihieiug he 'fuel u'ihiii ihe ironihustion chamber and foi uduiitingf ai? there mii ihiouifh for Supporting proper annihilation.;

it will he understood ha any olhei Siiilzihe arrangement of means for introducing;- an ini/ense form o1 combustion inizi* he uiiiizefi, und7 instead 01: the fom and eisposiion of ihe heating en ai? supplying' nie-ens pr-if Viousiy described, there may he, when a more intense form oi eoinhusiion is fieeired, he arrangement of hurnei and ai? 'po ih@ hiS'fraed in Fig. 5 of ihe duu'ings, in which 26 deSignutes a Wafer Cooled infiere or oumei inseiiexi in lshe paih of he incoming' ai? foi' liberating he fuel at vthef proper point :md at the required velocity foi* making ,ai i'iighi'v intense i'hime Whifh issiie fiom ho pori 2% over *ehe nmiei'iaiheing ee'te heu 'he eide-imei' is fo he einpioyeini (iepenilenily of assoeiation Wih a eiinkerug fipomfzit'us and iS will be conducted over a series of coolinV heart-hs, not shown but formed integral with the furnace structure and the cooling air permitted to pass over these. hearths will be sealed from passing upwardly through the discharge outlet 19 but will be conveyed to the passage or duct 25 and delivered as preheated air from the uppermost cooling hearth and over the lowermost hearthof the calcining apparatus.

By means of the above described invention there is provided a. calciner wherein it is possible to use flames of high thermal intensity or power in the interior of a calciner of the multiple hearth type and in direct contact with the material under treatment without injury to the met-al parts of the apparatus and without incurring undue heat losses to the outside. scribed constructed calciner practically all of the heat of the flames passes to the material under treatment and inasmuch as this heat is of high thermal intensity, the economical and rapid progress of calcination is assui-ed over and above that possible in a calciner of ordinary construction.

The invention has been illustrated in its preferred embodiment, but it will be understood that changes may be made in the details of construction without varying or departing from the nature and spirit of the invention and I wish to be understood as claiming the invention as broadly as the state of the art will ermit.

Having thus descri ed my invention what claim as new and desire to secure by letters lpatent is:

l. calciner for the described purpose, the same comprising an outer shell, a series of superposed hearths arranged therein in staggered relation, a series of rabble arms associated with and mova-bleover each of said hearths, a rotatable column carrying said arms centrally extended through the shell, a bottom hearth for the shell situated below the lowermost hearth of the series of hearths a distance in excess of the distance between said hearths to provide an enlarged combustion chamber, means for admitting combustible fuel and air for supporting combustion within the said chamber, a series of rabble arms carried by the rotatable column and moveable over the bottom hearth of the calciner for advancing calcined material to a discharge outlet, and a plow-shaped rabble tooth covering for each of the rabble arms associated with the said bottom hearth.

2. A calciner for the described purpose, the same comprising an outer shell provided with an inner insulated protected liner wall, a series of superposed hearths arranged therein in staggered relation, a bottom hearth for the shell situated a distance below the lowermost hearth of the Under the de-l series of hearths to providev a combustion chamber of enlarged area, rotatable. rabble arms associated with each of the hearths for moving material thereover, a plow-shaped rabble tooth covering for each of the rabble arms associated with the bottom hearth of the calciner, and means for admitting combustible fuel and air'for supporting combustion within the combustion chamber of the said calciner.

3. In a calciner for the described purpose, the combination with the combusti-on chamber thereof, of a plurality of rabble arms associated with the hearth of said chamber, means for admitting combustible fuel and air for supporting combustion within the said combustion chamber, and a plowshaped rabble tooth covering for each of the rabble arms associated with the hearth of said combustion chamber.

4. In a calciner for the described purpose, the combination with the combustion chamber thereof, aplurality of rotatable rabble arms associated with the hearth of said chamber, means for admitting combustible fuel and air for supporting combustion within the Said chamber, a plow-shaped rabble tooth covering removably7 secured to each of the rabble arms situated within the combustion chamber.

l5. In a calciner for the described purpose, the combination with the combustion chamber thereof, a bottom hearth for said chamber, a plurality of rabble arms rotatable within the chamber, means for admitting combustible fuel within the said chamber,

van annular fiue surrounding the hearth of the chamber for admitting air therein for supporting combustion, and a plow-shaped covering removably held to each of the rabble arms associated with the hearth of said chamber.

6. A calciner for thev described purpose,v

the same comprising an outer shell provided with an insulated inner lining wall, a series of superposed hearths arranged within the shell in staggered relation, a plurality of rabble arms associated with each of the said hearths for moving material thereover, means extended centrally within the calciner for supporting and imparting rotary movementl to the said rabble arms, a bottom hearth for the calciner situated a distance below the lowermost hearth of the mentioned series a distance in excess of that between the hearths of said series to provide a combustion chamber of enlarged area, means for admitting combustible fuel and air therein within said chamber for support-ing combustion, a plurality of rabble arms associated with the hearth of the combustion chamber for advancing calcined material thereover to Aa discharge outlet, and a removable plowshaped tooth covering for each of said rabble arms.

7. A calciner for the described purpose, the same comprising an-outer shell, a series of superposed hearths arranged therein in staggered relation, aseries of rabble arms associated with and movable over each of said hearths, a hollow rotatable column carrying said arms cent-rally extended through 'the shell, a bottom hearth for the shell situated below the lowermost hearth. of the series of superposed hearths a distance in eX- cess between said hearths to provide an enlarged combustion chamber, means for adrnittinar fuel within the combustion chamber and air therein for supporting combustion, and a series of rabble arms carried by the rotatable column and a plow-shaped rabble tooth covering for each of the said rabble arms, movable over the bottom hearth of the calciner and adapted Jfor working beneath the surface of the material therein under treatment.

8. In a calciner for the described purpose, the combination with the combustion chamber thereof, a bottom hearth for said chamber, a plurality of rabble arms associated with said hearth for movement thereover and adapted. for working beneath thesur tace of material therein for treatment, a removable plow-shaped tooth covering for each of said arms, and means tor admitting `fuel and air for supporting combustion within the said combustion chamber.

9. ln a calciner for the described purpose,

I the combination with the combustion chamber thereof, a plurality of rotatable rabble arms associated with the hearth of said chamber, means Jfor admitting fuel and air for supporting combustion within the said chamber and a plurality of plow-shaped rabble teeth removably secured to each of the rabble arms situated within the combustion chamber and adapted for working;` beneath the surface of thevmaterial within said chaina ber under treatment.

l0. ln a calciner for the described purpose, the combination with the outer shell thereof, of a series of superposed hearths arranged therein in staggered relation, a bottom hearth tor the outer shell situated a distance below the lowermost hearth of the series of hearths to provide a combustion chamber in excess of the distance between the hearths of said series, and a plurality of rabble arms movable over the said respective hearths and adapted to advance material dis charging thereon, a removable plow-shaped tooth coveringr secured to each of the rabble arms adapted for working over the hearth of the combustion chamber, means for ad mitting fuel within the combustion chamber and air therein to support combustion.V

ll. A calciner tor the described purpose, the same comprising),f an outer shell provided with an insulated inner liningr wall, a series of superposed hearths arranged within the shell in staggered relation, a plurality o rabble arms provided with rabble teeth associated with each of said hearths for advancing:l material thcreover, means for imparting,r rotary movement to the said rabble arms, a bottom hearth for the calciner situated a distance below the lowermost hearth of the mentioned series, a distance in excess of that between the hearths of said series to provide a combustion chamber of enlarged area, means for admitting fuel and air within the said chamber, and a plurality of rabble arms each provided with aremovable plow-shaped tooth covering associated with the hearth of the combustion chamber Jfor advancingy material thereover to a discharge outlet.

In testimony whereof I have signed my name to this specification.

ROBERT D. PlKE. 

